As a proponent of the technology age, I admit to throwing buzzwords around with the best (or worst) of us. Like my use of pidgin, however, I usually try to speak the language that's most appropriate to my audience. There are times when I slip, and use a term that I think is universal, but is not. This happened recently when I recommended to a colleague that she consider housing her computer systems in a data center. I went on and on extolling the pros and cons of doing so, until she interrupted me with "What the heck is a data center, anyway?"
Like many things technological, the term "data center" means different things to different people. In simplest terms, a data center is a room in which operational computers are stored. So, does the closet in the back with the server qualify as a data center? There are a few computers in the accounting office; what about that? How about the spare bedroom in a home office? Of course, the answer to all of these questions is no - although the IRS might let you write off the spare bedroom if you use enough of it.
By our accounts, there are several characteristics that must be fulfilled before a computer room can be considered a full-fledged data center.
First, it must be kept cool at all times. Obviously, this requires 24-hour air conditioning. Techies like to refer to this as "climate control." Computers last longer when they are kept cool. An added benefit of a climate-controlled room is that everyday dirt and dust is kept to a minimum since all windows and doors must be closed. Anybody who's ever opened a PC can attest that it attracts dust more than that "Pig Pen" kid in the Charlie Brown comics.
Second, a data center needs fire suppression. Water is not good! If one computer catches fire in the data center, spraying water all over the place will almost certainly render all the other equipment useless. Instead, a fire suppression system uses non-flammable chemicals to extinguish fires. A nasty by-product of this method is that such chemicals kill people if they are inhaled. So the fire suppression system needs to be sophisticated enough to allow anyone in the data center to temporarily shut it off so they can leave. After a short period of time, the chemical usually dissipates and the data center is safe to enter.
Power is also a critical component to a data center. While power drawn from the HECO grid is usually pretty clean, there are many circumstances (such as bad wiring in the building) that could cause power spikes or sags. The use of a good power conditioner will eliminate these anomalies and result in happier hardware.
Another power-related component found in many data centers is a facility-wide uninterruptible power supply or "UPS." A UPS provides battery-backup power in the event of a power outage. Sometimes, smaller UPSes can be sufficient for this purpose and a facility-wide UPS might not be necessary.
Most UPSes can be configured to communicate with computers to shut them off in case of a power outage. Ideally, however, a data center is equipped with a generator backup in addition to a UPS. In case of power outage, the UPS only needs to supply power to the equipment until the generator kicks in.
The final piece of the power component in a data center is a cutoff switch. Often referred to as "the big red button" because it is simply that - a big red button. This cutoff switch immediately cuts power to the entire data center and is a requirement of the Hawaii fire code for virtually all data centers. The "big red button" is usually used in case of fire or if a technician decides to stick his screwdriver into a socket to see if it's "hot."
Ever go into a room full of computers and see cables strewn haphazardly over the floor, along the walls and hanging from the ceilings? Oh, uh, me neither; but I've had friends tell me about them. A raised floor used to be a prerequisite for the data centers of old when mainframes ruled the world and there were only 3 stations on TV. Raised floors allow cables to be strewn haphazardly under the floor, thereby preventing people from tripping over them and pulling the plug on ol' HAL's DASD. Nowadays, with rack-mounted servers, blades, and other smaller computers and components, ladder racks can be more useful. A ladder rack allows cables to be strewn haphazardly overhead and out of the way.
Finally, in this day and age where everyone is concerned about security, the data center must be physically secure. Ideally, this would be through an electronic system that requires passcodes, keycards, or even biometric scans like retinal or fingerprint recognition. This will allow for easy updates to the security database, as people are granted or denied access. Once in the data center, a means to prevent access to the hardware itself is also desirable. This is usually effected through "cages" which are secured the "old fashioned way" with a lock and a key.
Now that you know what a data center is, what is it used for? Why might you need one? In Part 2 of this series, we'll examine what goes on in a data center, why you might need one and what to look for if you're in the market to utilize one.
